Ink cartridges used in inkjet printers include a printhead and one or more chambers that hold the ink. The printhead is a micro-electromechanical part that contains an array of miniature thermal resistors or piezoelectric transducers that are energized to eject small droplets of ink out of an associated array of orifices. The cartridge is mounted in a carriage in the printer and electrically connected to the printer controller. Under the direction of the controller, the cartridge is scanned back and forth across the print medium (usually paper) as resistors or transducers are energized to eject droplets of ink through the orifices on to the medium in the desired pattern.
Many color inkjet printers utilize a single three-chamber ink cartridge for printing color images—each chamber holds a different color ink, typically cyan, magenta and yellow ink. Some color inkjet printers utilize two three-chamber cartridges for printing higher quality color images, such as for photographs—the second cartridge typically holds light cyan, magenta and black inks. Recent developments of lower drop weight and dual drop weight inkjet printheads has made it possible to print higher quality color images with four colors—cyan, magenta, yellow and black. Hence, it would be desirable to have a new four-chamber design to provide an economical single cartridge for printing higher quality color images.